Tuberculosis is the leading cause of infectious death worldwide, killing approximately 1.6 million people each year. However, research and development for new TB drugs came to a virtual standstill after the 1960s. Today, a four-drug combination therapy exists, but it takes six months or more to be effective. This requires a degree of monitoring (See
Direct Observational Therapy, Short-course) beyond the capacity of the health infrastructure in many countries, and adequate TB treatment is not available to more than half of the most infectious cases. This can inhibit control of the disease and fuel the rise of
drug resistance (See
antimicrobial resistance). About 29% of deaths caused by antimicrobial infections today are due to drug-resistant TB. When infections become resistant to first-line drugs, more expensive therapies must be used to treat them. Lengthier treatment, often in hospitals, substantially increases health care costs as well as the economic burden on families and societies. The cost of treating a single case of multidrug-resistant TB (MDR-TB) or extensively drug-resistant TB (XDR-TB) can be thousands of times more expensive than treating drug-sensitive TB. TB is also the number one killer of people with
AIDS, but it is generally agreed that current TB treatments do not work well with the
antiretroviral drugs used to treat HIV. New, improved TB treatments are urgently needed. However, the TB drug market lacks sufficient financial incentives to stimulate broad-based investment from
pharmaceutical companies to invest in the new research required to sustain a treatment pipeline. The TB
epidemic is concentrated in developing countries where drugs must be low in cost to remain accessible. It does not generate the kind of revenue streams that private companies usually deem necessary to justify the research costs and strategic risks involved in pharmaceuticals. TB Alliance was designed to be the primary instrument to fill this vacuum and to ensure that new anti-TB drugs are affordable and accessible in endemic countries. ==History==